1. Field of the Invention
The present invention relates to multiple choke assemblies and to the reduction of mutual inductance effects occurring between chokes assembled in close proximity.
2. Description of the Prior Art
The desirability of placing chokes in series with electrocardiograph electrodes applied to the skin of a patient undergoing electrosurgery has been described in a paper prepared by Becker, Malhotra and Hedley-Whyte and appearing in the journal, "Anesthesiology", Volume 38, No. 2, February 1973. A similar recommendation appears in an article prepared by Finlay, Couchie, Boyce and Spencer and appearing in the journal, "Anesthesiology", Volume 41, No. 3, September 1974. In attempting to implement the recommendations of the foregoing articles, difficulties have been encountered due to the bulkiness of the chokes desired to be attached to the lead wires which are engaged to the patient contact electrodes. Attempts have been made to minimize the effects of such bulkiness by constructing patient blocks which house the requisite number of chokes and which may be conveniently mounted or supported near the patient's body. However, difficulties have been encountered with such patient blocks, such difficulties arising at times when, due to the monitoring configuration desired, one or more chokes of a multiple choke patient block is not to be connected to an electrode or when any one of the electrical connections to electrocardiograph monitoring electrodes is defective. Some of the difficulties appear to be attributable to mutual induction and/or capacitive coupling phenomena occurring between adjacent chokes. It is known, of course, to minimize such phenomena by appropriate shielding. However, the use of shielding in a patient block increases the bulkiness of the block in an undesirable fashion.
It is an object of the present invention to provide a new and improved multiple choke assembly. A further object of the present invention is to provide an improved patient block assembly for protecting patients undergoing electrosurgery from skin burns resulting from a leakage of electrosurgery currents through medical electrodes applied to the patient's body.